A method of manufacturing a fuel cell which enables organic matter of both an anode thereof and a cathode thereof to be removed efficiently is provided. A method of manufacturing a fuel cell, comprising a preparation step of preparing a fuel cell comprising a stack of a plurality of unit cells, each including polymer electrolyte and a catalyst layer, and a removal step of removing organic matter from the fuel cell, is provided. This removal step comprises: a first step of maintaining a voltage of the fuel cell at 0 V so as to desorb organic matter from the catalyst layer; a second step of raising a temperature inside the fuel cell so as to evaporate the desorbed organic matter; and a third step of exhausting the evaporated organic matter from the fuel cell.

A method conditions a fuel cell stack of a fuel cell system during a usage operation of the fuel cell system. The method determines that a conditioning of the fuel cell stack is to be carried out for increasing an electrical power provided by the fuel cell stack during usage operation. In addition, the method adjusts at least one operating parameter of the fuel cell system in order to increase a current flow through the fuel cell stack for conditioning the fuel cell stack during usage operation.

A power controlling apparatus includes a secondary battery (2) connected to an electrical device (4), and a fuel cell (3) connected to the electrical device (4) and the secondary battery (2). The fuel cell (3) has two non-generating modes including an idling mode and a halt mode, the fuel cell (3) suspending generation of power while being supplied with fuel in the idling mode, the fuel cell (3) stopping generation of power without fuel supply in the halt mode. The power controlling apparatus further includes a remainder estimator (11) to calculate the remaining number of starts representing the remaining number of available starts of the fuel cell (3), and a controller (16) to control the fuel cell (3) to be one of the two non-generating modes during a non-charging mode of the secondary battery (2), based on the remaining number of starts calculated by the remainder estimator (11).

A power controlling apparatus includes a secondary battery (2) connected to an electrical device (4), and a fuel cell (3) connected to the electrical device (4) and the secondary battery (2). The fuel cell (3) has two non-generating modes including an idling mode and a halt mode, the fuel cell (3) suspending generation of power while being supplied with fuel in the idling mode, the fuel cell (3) stopping generation of power without fuel supply in the halt mode. The power controlling apparatus further includes a remainder estimator (11) to calculate the remaining number of starts representing the remaining number of available starts of the fuel cell (3), and a controller (16) to control the fuel cell (3) to be one of the two non-generating modes during a non-charging mode of the secondary battery (2), based on the remaining number of starts calculated by the remainder estimator (11).

A fuel cell system includes a first fuel cell having first unit cells stacked together, a second fuel cell having second unit cells stacked together, a first voltage detector, a second voltage detector, and a controller. The first voltage detector detects voltage of the first unit cells for every “N” unit cells on average, and the second voltage detector detects voltage of the whole second fuel cell, or detects voltage of the second unit cells for every “M” unit cells on average. The controller determines whether any of the first unit cells is in a fuel deficiency state, by referring to a detection result of the first voltage detector, and performs a cancellation process to cancel the fuel deficiency state, on the first fuel cell that is in a power generating state, while stopping power generation of the second fuel cell, when an affirmative decision is obtained.

A fuel cell system includes: a cathode pressure control unit configured to control a pressure of a cathode gas to be supplied to the fuel cell stack on the basis of a load of the fuel cell stack; and an anode pressure control unit configured to control a pressure of an anode gas to be supplied to the fuel cell stack to become higher than the pressure of the cathode gas so that a differential pressure between the pressure of the anode gas and the pressure of the cathode gas becomes a predetermined differential pressure or lower. The anode pressure control unit controls, at a time of recovery from idle stop, the pressure of the anode gas to be supplied to the fuel cell stack to a recovery-time pressure, the recovery-time pressure being obtained by adding the predetermined differential pressure to a predetermined pressure corresponding to an atmosphere pressure.

A fuel cell system includes: a cathode pressure control unit configured to control a pressure of a cathode gas to be supplied to the fuel cell stack on the basis of a load of the fuel cell stack; and an anode pressure control unit configured to control a pressure of an anode gas to be supplied to the fuel cell stack to become higher than the pressure of the cathode gas so that a differential pressure between the pressure of the anode gas and the pressure of the cathode gas becomes a predetermined differential pressure or lower. The anode pressure control unit controls, at a time of recovery from idle stop, the pressure of the anode gas to be supplied to the fuel cell stack to a recovery-time pressure, the recovery-time pressure being obtained by adding the predetermined differential pressure to a predetermined pressure corresponding to an atmosphere pressure.

A fuel cell system includes: a fuel cell stack including a cathode passage and an anode passage formed thereinside; and a cathode gas supply passage including a first pump discharging cathode gas and connected to an inlet of the cathode passage. The fuel cell system further includes: a cathode off-gas exhaust passage including a back pressure valve and connected to an outlet of the cathode passage; and a circulation passage including a second pump discharging cathode off-gas to circulate cathode off-gas. The fuel cell system circulates cathode off-gas during idling operation to decrease cathodic potential, and increases an opening degree of the back pressure valve to greater than that during idling operation to decrease the cathode back pressure to less than that during idling operation after idling operation is shifted to load operation. This configuration promptly replaces gas in the fuel cell stack.

There is provided a control method of a flow regulating valve of an oxidizing gas in a fuel cell. In a load disconnected state that the fuel cell is electrically disconnected from a load, the control method gradually opens the flow regulating valve that is configured to supply the oxidizing gas to a cathode of the fuel cell by a predetermined valve opening each time from a full-close position or gradually closes the flow regulating valve by a predetermined valve opening each time from a full-open position, so as to gradually change a supply amount of the oxidizing gas introduced to the cathode and cause hydrogen transmitted from an anode to the cathode in the fuel cell to be oxidized. The control method measures an open circuit voltage of the fuel cell accompanied with oxidation of the hydrogen and stores at least one valve-opening position among valve-opening positions of the flow regulating valve at a predetermined number of timings including a timing when the measured voltage shifts to an increase or shifts to a decrease, as a regulation reference valve-opening timing.

There is provided a control method of a flow regulating valve of an oxidizing gas in a fuel cell. In a load disconnected state that the fuel cell is electrically disconnected from a load, the control method gradually opens the flow regulating valve that is configured to supply the oxidizing gas to a cathode of the fuel cell by a predetermined valve opening each time from a full-close position or gradually closes the flow regulating valve by a predetermined valve opening each time from a full-open position, so as to gradually change a supply amount of the oxidizing gas introduced to the cathode and cause hydrogen transmitted from an anode to the cathode in the fuel cell to be oxidized. The control method measures an open circuit voltage of the fuel cell accompanied with oxidation of the hydrogen and stores at least one valve-opening position among valve-opening positions of the flow regulating valve at a predetermined number of timings including a timing when the measured voltage shifts to an increase or shifts to a decrease, as a regulation reference valve-opening timing.